Touch grass bingo
Download the photo checker while you have Wi-Fi. It is about 150 MB and lets the game work with no signal.
How to play
Walk somewhere green and keep the phone in your pocket. When you spot something on the card, tap its square and take one photo. Fill a whole row, column or diagonal to win.
The middle square is never free. Put your hand on real grass and photograph it.
Card settings
Friends who enter the same code get the same card.